Atharna
Atharna was a water planet with large oceans and pleasure cruisers. It had a floating city called Moslin which contained the Statue of Kithal, one of the Wonders of the Universe. It was populated with colonists from all over the universe.
History
As a result of the Kotturuh crisis caused by the Tenth Doctor which altered time, (PROSE: The Knight, The Fool and the Dead) the planet was re-written as being a desert planet with two suns rather than one.
In this altered timeline, Felicity, Sophie Russell and Brian the Ood crashed down when Brian was contracted to kill Sophie. After Sophie fled into the town of Moslin, the Eighth Doctor landed, expecting to find a water planet as well as the statue. He helped them to Moslin in order to get them healed from their wounds, none the wiser that Brian was an assassin or that there was another survivor of the ship crashing due to them fabricating a story about bandits. (AUDIO: He Kills Me, He Kills Me Not)
On their way to Moslin, the Eighth Doctor recalls Godfather Death, the situation their in reminding him of it, and tells Brian the story. The story causes the two to debate the morals of death, wondering if it's a natural part of life or if it could be fought against. (PROSE: The Knight, The Fool and The Dead)
Sophie encountered Katherine Steele and Samson in an attempt to be hidden to safety away from Brian. They agree, hiding her in the cellar whilst Katherine prepared to encounter the assassin and ensure that no harm comes to her. Elsewhere in the town, Felicity, Brian and the Doctor arrive, with the Doctor leaving the other two in the care of Craddock, the local medic whilst he looks for the authorities to explain the faux story which he believed to be true. When the Doctor meets Sophie however, he's informed of the true story and he vows to help her.
Back in the clinic, Brian is now threatening Felicity's life despite her safe return being part of his contract, so that she would help him kill her wife. They make their way to the tavern, with Katherine and Samson attempting to disarm them. However, due to Brian not carrying any weapons and under the pretence that Brian is her bodyguard, these attempts fail. Due to him coming to the end of his patience, Brian decides to kill Felicity, whilst the Doctor, Sophie and Katherine devise a plan to rescue Felicity.
The group eventually gather in the bar, and while Craddock charges into Brian wherein he kills him, they're able to retrieve Felicity. Killing Craddock meant going through his shield which drained his ball, and thus Brian makes his escape to the Doctor's TARDIS back at the desert. The Doctor tells Brian that he'll take him off world if he breaks his contract with Felicity's father, and due to his weapon being drained he reluctantly agrees. However the TARDIS begins going haywire so the two jump in before it takes off.
Felicity and Sophie decide to stay on Atharna for a little while in order to lie low and out of Felicity's father's radar. (AUDIO: He Kills Me, He Kills Me Not)